Hitherto, a transparent conductive film obtained by stacking, on a transparent plastic film, a gas barrier layer and a transparent electrode in order from the bottom has been proposed for a transparent electrode of an image display apparatus provided with a liquid crystal device or an organic electroluminescence device (organic EL element) in order to implement a reduction in thickness, a reduction in weight, an increase in flexibility, and the like.
In this regard, for example, a transparent conductive film is disclosed in which a predetermined inorganic barrier thin film and a transparent conductive thin film of a metal oxide including indium oxide as a main component are formed on a substrate having a predetermined thickness (for example, see Patent Document 1).
That is, Patent Document 1 discloses a transparent conductive film obtained by forming, on a substrate, an inorganic barrier thin film that is formed of a metal oxide including silicon oxide as a main component and/or a metal nitride including silicon nitride as a main component, and a transparent conductive thin film of a metal oxide including indium oxide as a main component, the transparent conductive film having a predetermined oxygen transmittance rate after a bending test.
On the other hand, as a material for forming a transparent conductive layer in a transparent conductive film, tin-doped indium oxide (ITO) is mainly used. However, indium used as one of the forming materials is a rare metal and is relatively expensive. Therefore, application of a transparent conductive material other than indium has been examined.
In this regard, for example, a transparent conductive laminate is disclosed in which a silicon-containing inorganic layer having a predetermined thickness, a carbon nanotube layer having a predetermined thickness, and a transparent protective layer having a predetermined thickness are formed on at least one surface of a substrate having a predetermined thickness (for example, see Patent Document 2).
That is, Patent Document 2 discloses a transparent conductive laminate including a carbon nanotube layer as a conductive layer, in which a silicon-containing inorganic layer contains a predetermined coexistence phase of zinc sulfide and silicon dioxide.
Furthermore, a transparent conductive film and a manufacturing method therefor are proposed in which even when the film thickness of a ZnO-based transparent conductive thin film is thin, the transparent conductive film exhibits a low resistance value and has a low rate of change in resistance value even under a humidification and heating environment (for example, see Patent Document 3).
More specifically, Patent Document 3 proposes a transparent conductive film including: an aluminum oxide thin film or a silicon oxide thin film, which has an oxygen content corresponding to 60 to 90% of the stoichiometric value, formed as a first oxide thin film with a high visible-light transmittance on an organic polymer film substrate; a ZnO-based transparent conductive thin film formed on the first oxide thin film; and a second oxide thin film with a high visible-light transmittance and a water-vapor transmittance rate equal to or less than a predetermined value.